Apparatus for cleaning the interior surfaces of enclosures



Oct; 1966 J; R. ALEXANDER 3,276,694

APPARATUS FOR CLEANING THE INTERIOR SURFACES OF ENCLOSURES OriginalFiled Dec. 4, 1962 2 Sheets-Sheet l Mill/[1 012 rP/bse [IQ/er INVENTOR5,46 34 4 35 dZ/m/ fAiarAA/ozfi ATTORNEY Oct. 4, 1966 J. R. ALEXANDERAPPARATUS FOR CLEANING THE INTERIOR SURFACES OF ENCLOSURES 2Sheets-Sheet 2 Original Filed Dec. 4, 1962 INVENTOR. filwv 44 EXA/VDERATTORNEY United States Patent Claims. (Cl. 239-101 The inventiondescribed herein may be manufactured and used by or for the Governmentof the United States of America for governmental purposes without thepayment of any royalties thereon or therefor.

This application is a divisional application of applicants co-pendingapplication Serial No. 242,329, filed December 4, 1962, which in turn isa continuation-in-part of application Serial No. 766,160, filed October8, 1958, now abandoned.

This invention relates to the cleaning of metal surfaces in enclosuresto remove contaminants therefrom, where direct access to such surfacesis not possible or practical. For example, ferrous metal drums andbarrels are used extensively for the shipment and storage of petroleumand other products. Such drums are fabricated and because of this, theirinteriors have small cracks and crevices around the reinforcement at thebung hole and where separate parts are united. The surfaces that formthe interiors also have very small and minute pores, indentations, orcavities, and all of such pores, cavities, cracks, indentations andcrevices in use become filled with rust, scale, dirt and remnants of thevarious products with which the enclosure was filled in use. It isimportant that all traces of such contaminants be removed, even from thepores, cavities, cracks and crevices, to avoid undesired contaminationof fresh products to be stored and shipped in such enclosures.

In turbine casings, cargo tanks, trim tanks, heat exchangers, condenserand evaporator casings and the like, scale rust and other contaminantsform or accumulate on the interior exposed surfaces, and heretofore thethorough cleaning of such surfaces has been diificult, slow andexpensive, usually requiring the dismantling of such devices. To take anapparatus such as a turbine apart to clean its blades, for example, is aslow procedure and means taking it out of service for quite a period oftime which is not always practical.

It has been proposed to clean such enclosures by applying cleaningsolutions to such surfaces, such as by spraying the cleaning liquid assmall-droplets against the surfaces, but liquids applied to smallopenings such as pores, indentations, cracks and crevices, often formliquid bridges across them, instead of fully entering them. For example,upon spraying an ordinary Window screen with water, some of the openingsin the screen will have these liquid bridges formed across them thatprevent passage through them of ambient air. Many of the pores,recesses, indentations, or cracks of walls of an enclosure are so smallin face dimensions that a liquid sprayed against such walls will formliquid film bridges across such indentations, pores, recesses or cracks,and confine air that is within them against escape and also preventreplacement of the trapped air with the liquid. Hence a liquidcontaminant removing agent heretofore has been prevented from enteringmany of such small pores, recesses or cracks to act upon thecontaminants therein to remove them. When ordinary wet steam is admittedto such an enclosure, as a cleaning agent or a carrier of such an agent,the steam is so close to its condensation temperature that much of itimmediately condenses on such surfaces and forms liquid bridges acrosssuch small pores and indentations so that the uncondensed steam cannotenter and reach the contaminant.

In the case of scale accumulations on surfaces of metal within anenclosure, the scale commonly is formed largely of magnetite (Fe O andferric oxides attached to the metal surfaces by a thin layer of ferrousoxide (FeO) or an iron hydroxide layer. While the magnitite is quiteresistant to acids, the binding layer of ferrous oxide is easilydissolved by acid and when so dissolved it releases the magnetite andferric oxides part of the scale which then falls to the bottom of theenclosure. The rust scale is usually somewhat porous, and it is verydifiicul-t for cleaning liquids to penetrate the small pores of suchscales or other contaminants in order to reach the bonding material andby an interaction with the bonding material release the scale or othercontaminant. Attempts have been made to maintain contact with suchsurface by a cleaner or dilute acid solution for many hours to enablethe acid to diffuse slowly into such pores and indentations in the scaleand surfaces, but to fill a large enclosure even with a dilute acid orcleaning agent is not only a waste of acid or cleaner but is timeconsuming and the disposal of such large bodies of acid or cleaningagent often is a serious problem.

An object of the invention is to provide an improved apparatus forcleaning the metal interior surfaces of enclosures and apparatus andparts therein to remove contaminants therefrom, with which contaminantremoval may be accomplished rapidly .and easily with relatively simpleand inexpensive apparatus, with which the cleaning is exceptionallycomplete and thorough, and with minimum waste of cleaning agent, andwhich does not require dismantling of the enclosure.

Other objects and advantages will appear from the following descriptionof one example of the invention, and the novel features will beparticularly pointed out in connection with the appended claims.

In the accompanying drawings:

FIG. 1 is an elevation partly in section of an improved nozzle assemblyand connections for use in removing contaminants from the interior metalsurfaces of enclosures by the use of a fine, colloidal mist;

FIG. 2 is an enlarged section of the top portion of FIG. 1;

FIG. 3 is a schematic illustration of the manner of use of such a nozzleand connections in removal of contaminants from the interiors of metaldrums or barrels and similar containers; and

FIG. 4 is another schematic illustration of how such a nozzle and itsconnections may be used to clean the interior surfaces of enclosuressuch as cargo tanks, trim tanks, economizers, condensers, evaporatorsand turbine housings, without dismantling or extensively opening suchenclosures.

The invention and its practice will first be explained as applied to thecleaning of metal barrels and drums used for storage and transportationof petroleum products. Such drums are formed of ferrous materials andduring use scale and rust form on the interior surfaces, cracks,crevices, pores and indentations, and some of the petroleum or otherproducts stored or transported therein also remain on such interiorsurfaces and in many of such cracks, crevices, pores, and indentationswhen the drums are emptied and collect dirt. To clean such drums theyare disposed in an upended position, as shown schematically in FIG. 3and a nozzle assembly 10 inserted into the lower part of the drum 11through an open bung hole 12.

Through this nozzle assembly a stream of a preheated fluid is passedupwardly into the inverted drum until the drum walls are well heated,preferably as close to the 3 temperature of the steam as is practical.For example, I have heated the drums with steam at about 15 lbs. to 65lbs. pressure until after about one minute the exterior surfaces of thewalls of the drums are at temperatures between about 150 F. and 165 F.and the interior surfaces of those walls were at somewhat highertemperatures.

This preheating may also be caused by passing a stream of hot air intothe drum for a period of time sufiicient for the walls of the drum to bewell heated. The heating fluid, and particularly the steam, in additionto heating the Walls of the drum, tends to soften some of thecontaminants within the drum, such as to soften thick or viscousadhering remnants of the petroleum that had been stored therein.

After the preheating fluid is discontinued, a stream of heated fluid isimmediately passed into this preheated drum. This cleaning fluid is amixture of dry or superheated steam to which has been added a preheatedcleaning solution or agent of a selected type depending on the nature ofthe contaminants to be removed. A mixture of different cleaning agentsmay even be added to the steam. The liquid cleaning solution ispreheated well above room temperature and I have found that verysatisfactory results have been obtained when the cleaning solution oragent is preheated to about 130 F. or more before it is mixed at aboutthat temperature with the dry or superheated steam. This mixture ofsteam and liquid cleaning agent is then delivered through the nozzleassembly or other discharge means into the drum as a continuous streamof a very fine mist or fog, which fog is so fine that its particles canremain largely or entirely in suspension in fairly quiet air in the samemanner that moisture particles in a natural fog remain in suspension inthe air. For lack of a better term, this fineness may be designated ascolloidal, and the fog or mist so created may be called a colloidal fogor mist. The steam so used is dry or superheated, and I have found thatsteam under a pressure of from 15 to 65 lbs. gives good results formixing with the preheated cleaning liquid.

When this fine or colloidal fog or mist of the mixture of superheated ordry steam and the preheated liquid cleaner are introduced into thepreheated barrel or enclosure, the fog or mist will diffuse like a gasor vapor into the air in the pores, cracks, crevice and otherindentations of the interior surfaces of the enclosure, so that thecleaning agent will be immediately brought into contact with thecontaminants and act upon them. The steam being superheated and thecleaning liquid being so finely divided and hot, there will be little orno condensation of moisture as large droplets on the inner surfaces ofthe enclosure which could create large numbers of liquid bridges acrossthe cracks, crevices, pores and other indentations that would blockrepeated material penetration and diffusion by this fog of cleaningliquid into such small cavities and indentations for action on thecontaminants. When the contaminant is rust or scale the liquid cleaneris, or includes in it, a solution of a non-oxidizing mineral acid, suchas hydrochloric or sulphuric acid, for example, usually a dilutesolution of the acid, so that it will not react materially with themetal of the enclosure. For example, sulphuric acid may be used atconcentrations in water of at least about 0.20 percent by volume and upto 1% or more by volume, when it is not buffered. A buffering agent maybe added to the acid solution, if desired, in order to be able to use asomewhat stronger solution of the acid Without causing material damageto the metal of the enclosure. Such buffering agents for acids are wellknown and any of them may be used. By way of example, the detergent orcleaning agent for drums used to store petroleum products can be adilute aqueous caustic solution of about 3% to 5% strength. Thebuffering agent, if used with an acid, is frequently a salt of the acidused as the active agent or the salt of another and weaker acid,generally salts of acids with a low dissociation.

To facilitate the cleaning action due to the fog or mist, I prefer toadd a small .amount of a wetting agent to the cleaning solution, whichcauses more rapid and uniform contact and spreading of the cleaningsolution on the contaminant. In the case of ferrous metal enclosures,the addition to the cleaning solution of an iron phosphate may beadvantageous, since the phosphate provides a protective coating on thecleaned interior steel or iron surfaces of the enclosure withoutinterfering materially with the action of the acid, detergent, or othercleaning agent on the contaminant to be removed. When phosphates areincluded, the detergent or cleaning agent should be non-caustic. Thephosphate also fills some of the smallest pores, cracks, crevices orindentations and thus makes the interior surfaces of the enclosuresmoother, with less opportunity for subsequent contaminants to collectwhere they are the most difficult to reach and remove.

In the case of iron scale, which forms slowly on hot as well as coolsurfaces subjected to contact with water and air, as in turbines,evaporators, condensers, heat exchange units, and the like, the acidcleaning agent acts upon .the porous ferrous oxide (FeO) or an ironhyroxided layer, and since this ferrous oxide or hydroxide bindstogether the rest of the scale, largely of magnetite (Fe O and ferricoxides, it is unnecessary for the acid to act directly on the magnetiteor ferric oxides. The removal of the ferrous oxide, which is the binderfor the rest of the scale, releases the rest of the scale so that it candisintegrate into small pieces and fall off.

In the case of turbines, evaporators, condensers and like apparatus, thecleaning previously has generally been by taking the enclosure apart togain access to the parts to be cleaned. Then the interior contaminatedsurfaces are mechanically cleaned. It would be impractical to flood theinteriors of such assembled enclosures with a liquid cleaning agent,especially with the large volume of liquid necessary, with only a smallportion active and actually in direct contact with the contaminatedsurfaces. With this invention only a relatively small amount of thecleaning agent is required, it is unnecessary to dismantle the apparatusfor cleaning, and the time required for cleaning isvery small. In thecase of turbines the blades require cleaning at intervals and suchcleaning can, by this invention, be performed easily, effectively,rapidly and inexpensively. For turbines an ionized cleaning agent can beadvantageously employed in cleaning the blades. The interior surface-sof such apparatus have very small pores, cracks, crevices andindentations as exist in drums and barrels and the mist o-r fog beingsomewhat like a gas will diffuse with the air into all such crevices andindentations and the porous scale, and thus more rapidly reach andremove the contaminants and the ferrous oxide binders.

In the case of turbines, evaporators, heat exchangers, condensers andthe like, the nozzle assembly is inserted somewhat into the enclosuresof the same through an opening, and such enclosures usually have adrain. In FIG. 4, this is schematically shown where the enclosure 13 hasan opening 14 normally closed by a cap 15. The nozzle assembly 10 isinserted somewhat through this opening into the interior of theenclosure, such as by fitting it into a substitute vented cap 15. Theenclosure has a drain pipe 16 controlled by a valve 17 through which theloosened or released contaminants may be washed out. Of course theseenclosures will vary in size and shape, and in the arrangements andpositions of entrance openings and drains.

After the heated fog or mist has been passed into the enclosure of adrum or other enclosure until the contaminants are released or removedfrom the metal surfaces, this hot mist is discontinued, and a rinsestream of water, preferably and usually hot, is sprayed into the drum,barrel or enclosure to wash out the released contaminants. After this isdone, a stream of dry or superheated steam or dehumidified air, usuallyheated, is

passed into and through the drum, barrel or enclosure to dry it outrapidly.

Any suitable nozzle assembly which will create a fine or colloidal mistor fog may be used. One nozzle which produces a very fine mist or fog isdisclosed in US. patent to Day #2,116,879, issued May 10, 1938, but thenozzle assembly and connections to it which I have found to be mostsatisfactory to date, is disclosed in FIG. 1 to which reference may nowbe had. In this example of the nozzle assembly, a plurality of plates18, 19, 20, and 2 1 are arranged in superposed, spaced apart relationand spaced apart by endless walls 22, 23 and 24, all clamped together bybolts 25. This provides superposed, closed chambers 26, 27 and 28.Chamber 26 has an inlet opening 29 which is connected to a source ofhot, dry or dehumidified air. The chamber 27 has an inlet 30 forconnection to a source of dry or superheated steam, such as to steamunder a steam pressure of from about 15' lbs. to about 65 lbs. or more.The chamber 28 houses a simple turbine rot-or 31 that is rotatabletherein and a jet inlet passage '32 is provided in the wall 24 to directa stream of steam or compressed air against the rotor 31 to rotate it.The chamber 28 has an exit passage (not shown) for the propelling air orstream in a boss 33 on the wall 24.

Passing upwardly through the plates 19, 20 and 21 and rotor 31 androtatably mounted in the plates 20 and 21 is a tube 34 to which therotor 3-1 is fixed, so that the tube is rotated by the rotor. The tube34 extends below the plate 2 1 and there is connected through a valve34a to one end of a Venturi passage 35, the other end of which isconnected to a stream injector wherein the steam is directed by a jetnozzle 36 into the adjacent end of the Venturi passage, and the cleaningliquid is admitted to the area 37 around the jet from a conduit 38. Theconduit 38 is connected to the delivery port 39 of a reciprocating,single acting pump 40, operated by a crank device 41 that is driven by asuitable motor 42. The intake port of the pump is connected by a pipe 43to a source 44 of the cleaning liquid that has been preheated,preferably to a temperature of at least 130 F. The pump has an outwardlyopening check valve 39a at the delivery port 39, and also an inwardlyopening check valve 391; at its intake port. In an example, the pump wasoperated to deliver about one gallon of cleaning liquid per minute. Thelower end of the tube 34 has a swivel coupling to the pipe with theVenturi passage to enable rotation of the tube Without rotation of thevalve 34a and the Venturi passage. A stuffiing gland 45 is providedaround the tube 34 where it passes through the plate 20.

The opening 46 in the plate 19 through which the tube 34 passes islarger than the tube, and a sleeve 47 fixed at its lower end in theopening 46 extends upwardly along and spaced from the tube 34 throughand well beyond the plate 18. The opening 48 in the plate 18 throughwhich the tube 34 and sleeve 47 extend is larger than the sleeve 47 andanother sleeve 49 is fixed at its lower end in the opening 48 andextends upwardly along and spaced from the sleeve 47 and tube 34. Thetube 34 and the sleeves 47 and 49 have passages 50 and 51 between them.

The sleeves 47 and 49 extend to approximately the upper end of the tube34 and sleeve 47 at its upper end has an internal threading into whichis threaded an annular ring 52 made in two superposed, separatesections. A plurality of upwardly converging, tapered or jet passages 53are arranged at intervals around the ring 52 and discharge directlyupwardly. The upper end of the tube 34 is rotatably mounted in the ring52 by ball bearings 54 disposed at the horizontal junction between thesuperposed sections of the ring 52. The upper end of tube 34 terminatesin an upwardly and outwardly diverging seat 55 located slightly belowthe upper face of the ring 52 so as to provide an upright wall 56 thatextends upwardly beyond the seat 55. A spherical ball 57 is disposedupon 6 the seat 55 and is spaced slightly from the upright wall 56, butwith the ball extending upwardly beyond the ring 52. A stud 58 issecured to and extends upwardly from a spider or apertured partition 59across the passage of tube 34 and passes slidingly through the ball andcarries on its threaded, upper end a nut 60 that abuts the ball by whichthe possible displacement of the ball from its seat 55 may beselectively varied and adjusted. The sleeve 49 is secured at its upperend to the sleeve 47 by screws 61 and the annular exit 62 for the upperend of the passage 51 is outwardly and upwardly divergent.

When this nozzle assembly is inserted into an enclosure to be internallycleaned, suitable valves (not shown) in the connections to inlet 29, 30and 32 enable one to selectively control the flow of the dry orsuperheated steam to inlets 30 and 32 and hot dry dehumidified air toinlet 29. To preheat the enclosure the steam is passed through passage30 to chamber 27 and from there upwardly along passage 50 between thetube 34 and the sleeve 47, and it is discharged through jet passages 53into the enclosure to preheat it. After this preheating of the enclosureis accomplished this steam is left on and the mixture of steam from jet36 and the cleaning liquid is conveyed through the Venturi passage andupwardly through the tube 34 and discharged at its upper end between theball 57 and its seat 55. By adjusting the nut 60, the fineness of thedelivered mixture may be varied, and it is discharged as an upwardlydiverging conically shaped stream or curtain of fine mist. This streamor curtain of mist is similar to that produced by the nozzle disclosedin the Day patent, #2,116,879 above referred to, and the fine curtain ofthe mixture after passing between the ball and its seat strikes againstthe upright wall or shoulder 56 where it is broken up somewhat more intoa finer mixture.

Since the steam discharged from the jets 53 continues to escape, thejets of steam so formed will impinge against the curtain of the mixtureof steam and cleaning agents and further subdivide it into extremelyfine particles that are so fine as to largely remain in suspension inand diffuse through and displace some of the air of the enclosure, andthereby reach all parts of the enclosure interior and penetrate all ofthe small cavities on the interior surfaces. Since there is little or nocondensation of the steam in the preheated enclosure there will be fewor no liquid bridges across those cavities that would block entry intosuch cavities of the finely divided mist of the cleaning liquid. I havefound that the admission of the cleaning liquid into the tube 34 by thesteam injector in periodic pulses, due to the single stroke action ofthe pump appears to give a more effective cleaning action.

At the same time the turbine rotor is rotating the tube 34 so that thecurtain of discharge of the mixture of steam and cleaning solution orliquid will also rotate about the axis of rotation of the tube and theimpact of the steam from the non-rotating jets 53 upon the rotatingcurtain of the steam and cleaning mixture is very effective in breakingup the curtain into even finer particles of the cleaning liquid.

After this cleaning has continued until the contaminant is loosened orreleased, these streams are discontinued, and a rinsing solution,preferably hot, is passed into and through the enclosure to wash out theloosened and released contaminants, through a separate nozzle, or byalternately connecting tube 34 through conduit 34b and valve 340 to asource of rinsing water. After rinsing of the enclosure, the rinse wateris cut off and a stream of hot, dry, dehumidified air is passed throughinlet 29 into and along passage 51, and discharged through the annularorifice 62 into the enclosure until the interior of the enclosure isdry.

While the divided annular ring 52 at the discharge end of the nozzle mayhave a plurality of separate jet passages 53, arranged side by sidealong the ring, the passages may be, and preferably are, as shown,substantially a continuous, annular passage Where the inner and outerparts of each section of the ring are connected by a few radiallyextending cross arms or bars 53a arranged at intervals around eachsection of the ring, so that the discharge through jet passages 53 willbe, as nearly as practical, an approximately annular, thin, curtain ofsteam that impinges against the somewhat conical thin curtain of themixture of cleaning liquid and steam escaping from around the ball 57.

In the application of the fluid used for cleaning, rust removal, and theapplicataion of a rust inhibitor, the intermittent addition of thecleaning solution to the dry steam, such as caused by the single actingpump 40, for discharge through rotating tube 34 aids materially inpreventing the formation of liquid bridges across any of the smallindentations, cracks, recesses and crevices, and hence results in arapid and effective cleaning of the interiors of the enclosures. It ispostulated that the dry or superheated steam discharged into theenclosure between pressure strokes of the pump 44 will evaporate anycleaning liquid or water that might possibly condense as liquid bridgesacross any of the indentations, pores or crevices in the surfaces beingcleaned and interfere with entry of the colloidal particles of cleaningfluid into the indentations, pores, recesses or crevices in the interiorsurfaces of the enclosure or objects therein. If liquid cleaning agentsare delivered continuously and rapidly, such as by a stream in liquidform impinging upon an open screen, there is a tendency for the liquidto form liquid bridges across the screen openings or across the faces ofpores, recesses, indentations, cracks and crevices that slow or deterthe action of the cleaning agents employed, in penetrating such bridges.The danger of formation of bridges is lessened by the intermittentdelivery of the cleaning liquid to the steam injector.

In one example of the practice of the invention, the single acting pumpwas operated at about 300 revolutions per minute and delivered on eachdischarge or feed stroke about 0.9 ounce per stroke which for 150 feedor discharge strokes would deliver about 135 ounces of cleaning solutionper minute. At the same time the steam was supplied continuously atabout 3.5 to 4 lbs. per minute at 50 lbs. gage pressure, which appearedto be ample to completely convert the cleaning liquid being used into afine mist with sufficient energy and heat to accomplish the desiredresults. Steam at higher pressures of 100 lbs. gage pressure or higherwould have given swifter cleaning. Because of this intermittent additionof the cleaning agent, along with continued flow of the dry orsuperheated steam, the concentration of the cleaning agent can begreater than might be used if continued contact of the liquid with thecontaminated surface was employed. In the use of acids to remove rustand scale, the intermittent admission of the acid along with thediluting dry or superheated steam that is being continuously dischargedinto the disclosure enables one to use much stronger or moreconcentrated acid solutions without danger of damage to the metal of theenclosure by such acids. Concentrations of mineral acids of up to ormore can be safely used since the steam dilutes the acid further and thetime of contact of the acid with the metal is merely a matter usually ofonly a few minutes and is followed promptly by a water rinse.

The dry and superheated steam applied between the strokes of the pumpkeeps the interior surfaces or areas of the enclosure and of objectstherein dry, hot and free from any condensation on those surfaces. Whenthe steam pressure as supplied is increased, it is possible to locatethe discharge nozzle, such as is disclosed in the drawings, for example,at a greater distance from the surfaces to be cleaned, because theincreased steam pressure would impart more energy to the dischargedsteam and thus allow for this increase in distance from the dischargenozzle to the interior areas, objects, or surfaces to be .cleaned. F rlarge tanks, such as cargo tanks of ships or large stationary storagetanks, this is advantageous and more economical.

In the cleaning of surfaces that are contaminated with oils, theaddition to the cleaning liquid of a small amount of any emulsionbreaking agent, such as carbon tetrachloride for example, willaccelerate and more effectively complete the cleaning by breaking theemulsions of the oils adhering to any surfaces within an enclosure andfacilitate their removal from such surfaces.

It will be understood that various changes in the details, steps,materials and arrangements and constructions of parts, which have beenherein described and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims.

I claim:

1. Apparatus for use in cleaning the exposed metal interior surfaces ofan enclosure to remove adhering contaminants from such surfaces, whichcomprises:

one tube having an inlet at one end, terminating at its other end in anannular, outwardly facing and divergent end seat,

a ball engaging said seat,

means for adjustably limiting movement of said ball away from said seatto vary the thickness of a cone of a fluid passing said ball,

another tube larger than and surrounding said one tube and terminatingat one end adjacent to said ball in a plurality of jet nozzles that arepointed toward the side of a cone of a fluid that may pass said ballfrom said one tube,

a tubular casing surrounding, larger than and extending along saidanother tube and terminating at one end in a discharge port, adjacentsaid ball,

means for closing the other ends of said another tube and said casing,

means for supplying air to the space between said casing and saidanother tube at a location remote from said discharge port,

means for supplying steam to the space between said tubes at a locationremote from said nozzles, and

a conduit connected to the other end of said one tube for supplying afluid thereto.

2. The apparatus according to claim 1, wherein said conduit has aportion of its passage of venturi shape with an injector in front ofsaid venturi passage.

3. The apparatus according to claim 2, and means connected to saidinject-or at one side of the injector nozzle for supplying liquid to theinjector in pulses.

4. The apparatus according to claim 1, wherein said one tube is mountedto rotate about its longitudinal axis within said another tube, andpower means connected to said one tube for causing its such rotation.

5. Apparatus for use in cleaning the exposed metal interior surfaces ofan enclosure to remove adhering contaminants from such surfaces, whichcomprises:

one tube having an inlet at one end, terminating at its other end in anannular, outwardly facing and divergent end seat,

a ball engaging said seat,

means for adjustably limiting movement of said ball away from said seatto vary the thickness of a cone of a fluid passing said ball,

another tube larger than and surrounding said one tube and terminatingat one end adjacent to said ball in a plurality of jet nozzles that arepointed toward the side of a cone of a fluid that may pass said ballfrom said one tube,

a tubular casing surrounding, larger than and extending along saidanother tube and terminating at one end in a discharge port adjacentsaid ball,

means for closing the other ends of said another tube and said casing,

means for supplying a fluid to the space between said casing and saidanother tube at a location remote from said discharge port,

means for closing the space between said tubes at a location remote fromsaid nozzles,

means for supplying a fluid to the space between said tubes at saidlocation remote from said nozzles, and

a conduit connected to the other end of said one tube for supplying afluid thereto.

6. The apparatus according to claim 5, wherein said means for closingthe other end of said another tube and casing and said means for closingthe space between said tubes at a location remote from said nozzlescomprises a plurality of plates arranged in superposed spaced apartrelation by endless walls, all secured together by clamping means.

7. The apparatus according to claim 5, wherein said means foradjust-ably limiting movement of said ball away from said seat comprisesan apertured partition across the passage of said one tube, saidapertured partition having a stud secured thereto and extending upwardlytherefrom, said ball having a passage therethrough sli-dingly receivingsaid stud, said stud being of greater length than the passage throughsaid ball, said stud being threaded, and a nut on the outer end of thethreaded stud for engaging the ball and by which the possibledisplacement of the ball from its seat may be varied.

8. The apparatus according to claim 7, wherein said apertured partitionhas threaded engagement within the upper end of said one tube, wherebyit is adjustably held in said tube relative to said seat and ball.

9. The apparatus according to claim 5 wherein said another tube whichterminates in a plurality of jet nozzles, has an internal threading intowhich is threaded an annular ring having an upwardly converging taperedor jet annular passage therein with radially extending cross barsarranged at intervals around said ring in said annular tapered passage,and providing said jet nozzles.

10. The apparatus according to claim 9 in which said annular ring ismade in two superposed, separate sections, with ball bearings disposedin a groove at the junction between the superposed sections of the ringand in a cooperating groove in the upper end of said one tube, forrotatably mounting said tube in said ring.

References Cited by the Examiner UNITED STATES PATENTS 892,778 7/ 1908Townsend 239-424 X 1,236,073 8/ 1917 Fesler 239-424 X 2,017,042 10/1935Dougherty.

2,811,975 11/1957 Tatibana 134-102. 2,818,076 12/1957 Erling 134102CHARLES A. WILLMUTH, Primary Examiner.

ROBERT L. BLEUTGE, Assistant Examiner.

1. APPARATUS FOR USE IN CLEANING THE EXPOSED METAL INTERIOR SURFACES OFAN ENCLOSURE TO REMOVE ADHERING CONTAMINANTS FROM SUCH SURFACES, WHICHCOMPRISES: ONE TUBE HAVING AN INLET AT ONE END, TERMINATING AT ITS OTHEREND IN AN ANNULAR, OUTWARDLY FACING AND DIVERGENT END SEAT, A BALLENGAGING SAID SEAT, MEANS FOR ADJUSTABLY LIMITING MOVEMENT OF SAID BALLAWAY FROM SAID SEAT TO VARY THE THICKNESS OF A CONE OF A FLUID PASSINGSAID BALL, ANOTHER TUBE LARGER THAN AND SURROUNDING SAID ONE TUBE ANDTERMINATING AT ONE END ADJACENT TO SAID BALL IN A PLURALITY OF JETNOZZLES THAT ARE POINTED TOWARD THE SIDE OF A CONE OF A FLUID THAT MAYPASS SAID BALL FROM SAID ONE TUBE, A TUBULAR CASING SURROUNDING, LARGERTHAN AND EXTENDING ALONG SAID ANOTHER TUBE AND TERMINATING AT ONE END INA DISCHARGE PORT, ADJACENT SAID BALL, MEANS FOR CLOSING THE OTHER END OFSAID ANOTHER TUBE AND SAID CASING, MEANS FOR SUPPLYING AIR TO THE SPACEBETWEEN SAID CASING AND SAID ANOTHER TUBE AT A LOCATION REMOTE FROM SAIDDISCHARGE PORT,